The present invention is a battery powered, joy stick controlled for speed and direction, easily folding, light weight wheel chair.
The marketplace for powered wheelchairs is mainly populated by devices with heavy steel frames supporting heavy upholstered chairs and having big motors and heavy automobile type storage batteries. These robust components together make a wheelchair so heavy that, while it functions well as a powered wheelchair, it becomes very burdensome to transport from one venue to another. Hence, there is a need for a wheelchair that is light weight and nimble, and whose light weight enables smaller motors and smaller batteries to perform equally as well as its heavy counterparts, resulting in a truly portable mobility aid that can be transported in a back seat floor or the trunk of a car, rather than a specialized van.
According to this invention, the need mentioned above is met by a battery powered, joystick controlled wheelchair including a battery by which a supply of power can be provided, a joystick by which voltages proportionate to degrees of lean from a neutral position can be produced from the supply of power, and a master power switch by which the supply of power to the joystick can be turned on and off. A determination is made as to whether the voltages produced are forward or reverse direction voltages, and pulse width modulation, resulting in a pulse train, is provided. The pulse train is amplified to deliver driving power with a polarity consistent with a detected direction, and motors are driven by the driving power and, in turn, drive the wheelchair.
In the particular embodiment disclosed, the motors are dc motors, and the battery is a 12 volt battery. The master power switch, moreover, is interposed between the battery and the joystick. The wheelchair is preferably a folding wheelchair.
The wheelchair preferably has a frame which is at least partly constructed from metal tubing. Wheels for locomotion are driven by the motors, and pairs of plates, between which each of the wheels for locomotion is mounted, are provided. One plate of each of the pairs of plates is a mounting plate to which one of the motors is mounted. Screws mount each of the motors to the respective mounting plate.
A method of operating the battery powered, joystick controlled wheelchair includes providing a supply of battery power which can be turned on and off to a joystick, producing voltages from the supply of battery power which are proportionate to degrees to which the joystick leans from a neutral position, and detecting whether the voltages produced are forward or reverse direction voltages. Pulse width modulation, resulting in a pulse train, is provided, and the pulse train is amplified to deliver driving power with a polarity consistent with a detected direction. Motors are driven with the driving power and, in turn, drive the wheelchair.
Another feature of the invention concerns a battery storage assembly adapted for use in a battery powered, joystick controlled wheelchair. The battery storage assembly includes a battery container defining a volume within which the battery can be received. A lid is hinged on the battery container so as to be movable between an open position and a shut position. The lid serves as a platform upon which the battery can be laid. A battery contact is adapted to contact a battery terminal when the lid is moved to the shut position, and a latch can be used to lock the lid in the shut position. The latch is used to press the battery terminal to the battery contact when the latch locks the lid in the shut position. The battery storage assembly further includes an electronics board interconnected with the battery contact, and a cover enclosing the electronics board.
Other features and advantages of the invention will be clear from the description of the invention which follows.